The optimized wavelength combinations of two broadband sources for white light interferometry

Two broadband sources can be used in combination in white light interferometry to simplify the problem of central fringe identification. In this paper, a method for selecting the optimum wavelength combinations of such sources is presented. The results are obtained from a theoretical analysis and computer simulations, verified by experiment. It has been shown that the minimum signal-to-noise ratio required by the system to identify the central fringe position can be greatly reduced by using the optimum wavelength combination. >